Research will be done in two areas: Dextran Biosynthesis: 1. We will purify and characterize the enzymes for Strep. mutans which are involved in the synthesis of water soluble and water-insoluble dextrans. 2. Studies will be made of the role of potential primers in the synthesis reaction and efforts will be directed at developing effective enzymic inhibitors. Microtubule Chemistry: 1. The mechanism for presteady state and steady state microtubule assembly will be studied. 2. The role of microtubule-associated proteins in the regulation of microtubule assembly will be analyzed.